(1) Field of the Invention
The present invention relates to a display apparatus which displays information, and in particular to a hands-free operation technique for head-worn displays such as HMDs (head-mounted displays).
(2) Description of the Related Art
Conventionally, hands-free operation methods which eliminate the need for manual user operation have been proposed for head-worn displays such as HMDs (head-mounted displays). Typical hands-free operation methods include a method which uses an eye camera (camera which takes images of eyeballs).
For example, there is a method which estimates a user's point of regard by taking images of the user's eyeballs with an eye camera and analyzing their moving images (e.g., refer to Japanese Unexamined Patent Application Publication No. 8-286141). This method makes it possible to estimate a display element watched by the user out of multiple display elements displayed on a screen of an HMD or the like. This allows the user to operate the HMD by moving the line of sight without button operation or the like.
Also, there are methods for estimating a direction user is looking in, using something other than an eye camera.
For example, there is a method which estimates the direction user is looking in, based on output from an angular velocity sensor mounted on the head of the user (e.g., refer to Japanese Unexamined Patent Application Publication No. 7-24141). This method makes it possible to estimate, to some extent, an area the user is looking at.